P: Current prime number in use.
c: composite number (not prime)
A: 3p
B: 2p
∞+#: keep adding that number ∞ times, letting all sums =c

1. let p = lowest still listed #. p starts at the number 3.
2. 1 ∞+1 = Starting list. (2,3,4,5,6,7,...)
3. Remove 9 from the list. (is the only number the formula skips)
4. 2 ∞+2=c
5. A ∞+B=c
6. remove all c's from list
7. repeat step 5 and 6 ∞ times, leting p = the lowest still listed number.

Only Prime numbers will remain
The only problem with this theory is that some numbers will be removed from the list multiple times.
I apologize for my improper math grammar, I don’t know the correct symbols to use so I made my own.